Japanese Patent Laying-Open No. 9-117016 discloses an electric vehicle in which left and right front wheels are driven with separate motors respectively. In the electric vehicle, the left and right front wheels are driven with separate motors respectively and torque distribution between left and right motors is varied based on steering of a steering wheel.
According to the electric vehicle, as an effect equivalent to that of power steering can be obtained by varying torque distribution between the left and right motors, the need for a power steering system can be obviated.
On the other hand, Japanese Patent Laying-Open No. 9-117016 does not consider measures against failure of a steering apparatus providing a steering angle to the front wheels. Namely, if the steering apparatus fails, the vehicle can no longer run.
In particular in a steering apparatus adopting a steer-by-wire system that has attracted attention in recent years, as the steering wheel and the front wheels are mechanically separate, improvement in reliability of the steering system is an important issue.